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Components:
Clozapine
Method of action:
Antipsychotic, Antiserotonin, Psychoanaleptics, Psycholeptics, Sedative
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Medically reviewed by Militian Inessa Mesropovna, PharmD. Last updated on 2020.01.21

Name of the medicinal product

Klozapol

Qualitative and quantitative composition

Clozapine

Therapeutic indications

The information provided in Therapeutic indications of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Therapeutic indications in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
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Treatment-Resistant Schizophrenia

FAZACLO is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the risks of severe neutropenia and of seizure associated with its use, FAZACLO should be used only in patients who have failed to respond adequately to standard antipsychotic treatment.

The effectiveness of clozapine in treatment-resistant schizophrenia was demonstrated in a 6-week, randomized, double-blind, active-controlled study comparing clozapine and chlorpromazine in patients who had failed other antipsychotics.

Reduction In The Risk Of Recurrent Suicidal Behavior In Schizophrenia Or Schizoaffective Disorder

FAZACLO is indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for reexperiencing suicidal behavior, based on history and recent clinical state. Suicidal behavior refers to actions by a patient that put him/herself at risk for death.

The effectiveness of clozapine in reducing the risk of recurrent suicidal behavior was demonstrated over a two-year treatment period in the InterSePT™ trial.

Treatment-Resistant Schizophrenia

Klozapol is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the risks of severe neutropenia and of seizure associated with its use, Klozapol should be used only in patients who have failed to respond adequately to standard antipsychotic treatment.

The effectiveness of clozapine in treatment-resistant schizophrenia was demonstrated in a 6-week, randomized, double-blind, active-controlled study comparing clozapine and chlorpromazine in patients who had failed other antipsychotics.

Reduction In The Risk Of Recurrent Suicidal Behavior In Schizophrenia Or Schizoaffective Disorder

Klozapol is indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for reexperiencing suicidal behavior, based on history and recent clinical state. Suicidal behavior refers to actions by a patient that put him/herself at risk for death.

The effectiveness of clozapine in reducing the risk of recurrent suicidal behavior was demonstrated over a two-year treatment period in the InterSePT™ trial.

Dosage (Posology) and method of administration

The information provided in Dosage (Posology) and method of administration of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Dosage (Posology) and method of administration in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
Orally disintegrating

Required Laboratory Testing Prior To Initiation And During Therapy

Prior to initiating treatment with FAZACLO, a baseline ANC must be obtained. The baseline ANC must be at least 1500/μL for the general population, and at least 1000/μL for patients with documented Benign Ethnic Neutropenia (BEN). To continue treatment, the ANC must be monitored regularly.

Important Administration Instructions

FAZACLO orally disintegrating tablets should be immediately placed in the mouth after removing the tablet from the blister pack or bottle. The tablet disintegrates rapidly after placement in the mouth. The tablets can be allowed to disintegrate, or they may be chewed. They may be swallowed with saliva. No water is necessary for administration.

The orally disintegrating tablets in a blister pack should be left in the unopened blister until the time of use. Just prior to use, peel the foil from the blister and gently remove the orally disintegrating tablet. Do not push the tablets through the foil, because this could damage the tablet.

Dosing Information

The starting dose is 12.5 mg once daily or twice daily. The total daily dose can be increased in increments of 25 mg to 50 mg per day, if well-tolerated, to achieve a target dose of 300 mg to 450 mg per day (administered in divided doses) by the end of 2 weeks. Subsequently, the dose can be increased once weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. To minimize the risk of orthostatic hypotension, bradycardia, and syncope, it is necessary to use this low starting dose, gradual titration schedule, and divided dosages.

FAZACLO can be taken with or without food.

Maintenance Treatment

Generally, patients responding to FAZACLO should continue maintenance treatment on their effective dose beyond the acute episode.

Discontinuation Of Treatment

Method of treatment discontinuation will vary depending on the patient's last ANC:

  • See Tables 2 or 3 for appropriate ANC monitoring based on the level of neutropenia if abrupt treatment discontinuation is necessary because of moderate to severe neutropenia.
  • Reduce the dose gradually over a period of 1 to 2 weeks if termination of FAZACLO therapy is planned and there is no evidence of moderate to severe neutropenia.
  • For abrupt clozapine discontinuation for a reason unrelated to neutropenia, continuation of the existing ANC monitoring is recommended for general population patients until their ANC is ≥ 1500/μL and for BEN patients until their ANC is ≥ 1000/μL or above their baseline.
  • Additional ANC monitoring is required for any patient reporting onset of fever (temperature of 38.5°C or 101.3°F, or greater) during the 2 weeks after discontinuation.
  • Monitor all patients carefully for the recurrence of psychotic symptoms and symptoms related to cholinergic rebound such as profuse sweating, headache, nausea, vomiting, and diarrhea.

Re-Initiation Of Treatment

When restarting FAZACLO in patients who have discontinued FAZACLO (i.e., 2 days or more since the last dose), re-initiate with 12.5 mg once daily or twice daily. This is necessary to minimize the risk of hypotension, bradycardia, and syncope. If that dose is well-tolerated, the dose may be increased to the previously therapeutic dose more quickly than recommended for initial treatment.

Dosage Adjustments With Concomitant Use Of CYP1A2, CYP2D6, CYP3A4 Inhibitors Or CYP1A2, CYP3A4 Inducers

Dose adjustments may be necessary in patients with concomitant use of: strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin); moderate or weak CYP1A2 inhibitors (e.g., oral contraceptives, or caffeine); CYP2D6 or CYP3A4 inhibitors (e.g., cimetidine, escitalopram, erythromycin, paroxetine, bupropion, fluoxetine, quinidine, duloxetine, terbinafine, or sertraline); CYP3A4 inducers (e.g., phenytoin, carbamazepine, St. John's wort, and rifampin); or CYP1A2 inducers (e.g., tobacco smoking) (Table 1).

Table 1: Dose Adjustment in Patients Taking Concomitant Medications

Co-medications Scenarios
Initiating FAZACLO while taking a co-medication Adding a co-medication while taking FAZACLO Discontinuing a co-medication while continuing FAZACLO
Strong CYP1A2 Inhibitors Use one third of the FAZACLO dose. Increase FAZACLO dose based on clinical response.
Moderate or Weak CYP1A2 Inhibitors Monitor for adverse reactions. Consider reducing the FAZACLO dose if necessary. Monitor for lack of effectiveness. Consider increasing FAZACLO dose if necessary.
CYP2D6 or CYP3A4 Inhibitors
Strong CYP3A4 Inducers Concomitant use is not recommended. However, if the inducer is necessary, it may be necessary to increase the FAZACLO dose. Monitor for decreased effectiveness. Reduce FAZACLO dose based on clinical response.
Moderate or Weak CYP1A2 or CYP3A4 Inducers Monitor for decreased effectiveness. Consider increasing the FAZACLO dose if necessary. Monitor for adverse reactions. Consider reducing the FAZACLO dose if necessary.

Renal Or Hepatic Impairment Or CYP2D6 Poor Metabolizers

It may be necessary to reduce the FAZACLO dose in patients with significant renal or hepatic impairment, or in CYP2D6 poor metabolizers.

Required Laboratory Testing Prior To Initiation And During Therapy

Prior to initiating treatment with Klozapol, a baseline ANC must be obtained. The baseline ANC must be at least 1500/μL for the general population, and at least 1000/μL for patients with documented Benign Ethnic Neutropenia (BEN). To continue treatment, the ANC must be monitored regularly.

Important Administration Instructions

Klozapol orally disintegrating tablets should be immediately placed in the mouth after removing the tablet from the blister pack or bottle. The tablet disintegrates rapidly after placement in the mouth. The tablets can be allowed to disintegrate, or they may be chewed. They may be swallowed with saliva. No water is necessary for administration.

The orally disintegrating tablets in a blister pack should be left in the unopened blister until the time of use. Just prior to use, peel the foil from the blister and gently remove the orally disintegrating tablet. Do not push the tablets through the foil, because this could damage the tablet.

Dosing Information

The starting dose is 12.5 mg once daily or twice daily. The total daily dose can be increased in increments of 25 mg to 50 mg per day, if well-tolerated, to achieve a target dose of 300 mg to 450 mg per day (administered in divided doses) by the end of 2 weeks. Subsequently, the dose can be increased once weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. To minimize the risk of orthostatic hypotension, bradycardia, and syncope, it is necessary to use this low starting dose, gradual titration schedule, and divided dosages.

Klozapol can be taken with or without food.

Maintenance Treatment

Generally, patients responding to Klozapol should continue maintenance treatment on their effective dose beyond the acute episode.

Discontinuation Of Treatment

Method of treatment discontinuation will vary depending on the patient's last ANC:

  • See Tables 2 or 3 for appropriate ANC monitoring based on the level of neutropenia if abrupt treatment discontinuation is necessary because of moderate to severe neutropenia.
  • Reduce the dose gradually over a period of 1 to 2 weeks if termination of Klozapol therapy is planned and there is no evidence of moderate to severe neutropenia.
  • For abrupt clozapine discontinuation for a reason unrelated to neutropenia, continuation of the existing ANC monitoring is recommended for general population patients until their ANC is ≥ 1500/μL and for BEN patients until their ANC is ≥ 1000/μL or above their baseline.
  • Additional ANC monitoring is required for any patient reporting onset of fever (temperature of 38.5°C or 101.3°F, or greater) during the 2 weeks after discontinuation.
  • Monitor all patients carefully for the recurrence of psychotic symptoms and symptoms related to cholinergic rebound such as profuse sweating, headache, nausea, vomiting, and diarrhea.

Re-Initiation Of Treatment

When restarting Klozapol in patients who have discontinued Klozapol (i.e., 2 days or more since the last dose), re-initiate with 12.5 mg once daily or twice daily. This is necessary to minimize the risk of hypotension, bradycardia, and syncope. If that dose is well-tolerated, the dose may be increased to the previously therapeutic dose more quickly than recommended for initial treatment.

Dosage Adjustments With Concomitant Use Of CYP1A2, CYP2D6, CYP3A4 Inhibitors Or CYP1A2, CYP3A4 Inducers

Dose adjustments may be necessary in patients with concomitant use of: strong CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin, or enoxacin); moderate or weak CYP1A2 inhibitors (e.g., oral contraceptives, or caffeine); CYP2D6 or CYP3A4 inhibitors (e.g., cimetidine, escitalopram, erythromycin, paroxetine, bupropion, fluoxetine, quinidine, duloxetine, terbinafine, or sertraline); CYP3A4 inducers (e.g., phenytoin, carbamazepine, St. John's wort, and rifampin); or CYP1A2 inducers (e.g., tobacco smoking) (Table 1).

Table 1: Dose Adjustment in Patients Taking Concomitant Medications

Co-medications Scenarios
Initiating Klozapol while taking a co-medication Adding a co-medication while taking Klozapol Discontinuing a co-medication while continuing Klozapol
Strong CYP1A2 Inhibitors Use one third of the Klozapol dose. Increase Klozapol dose based on clinical response.
Moderate or Weak CYP1A2 Inhibitors Monitor for adverse reactions. Consider reducing the Klozapol dose if necessary. Monitor for lack of effectiveness. Consider increasing Klozapol dose if necessary.
CYP2D6 or CYP3A4 Inhibitors
Strong CYP3A4 Inducers Concomitant use is not recommended. However, if the inducer is necessary, it may be necessary to increase the Klozapol dose. Monitor for decreased effectiveness. Reduce Klozapol dose based on clinical response.
Moderate or Weak CYP1A2 or CYP3A4 Inducers Monitor for decreased effectiveness. Consider increasing the Klozapol dose if necessary. Monitor for adverse reactions. Consider reducing the Klozapol dose if necessary.

Renal Or Hepatic Impairment Or CYP2D6 Poor Metabolizers

It may be necessary to reduce the Klozapol dose in patients with significant renal or hepatic impairment, or in CYP2D6 poor metabolizers.

Contraindications

The information provided in Contraindications of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Contraindications in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
Orally disintegrating

Hypersensitivity

FAZACLO is contraindicated in patients with a history of serious hypersensitivity to clozapine (e.g., photosensitivity, vasculitis, erythema multiforme, or Stevens-Johnson Syndrome) or any other component of FAZACLO.

Hypersensitivity

Klozapol is contraindicated in patients with a history of serious hypersensitivity to clozapine (e.g., photosensitivity, vasculitis, erythema multiforme, or Stevens-Johnson Syndrome) or any other component of Klozapol.

Special warnings and precautions for use

The information provided in Special warnings and precautions for use of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Special warnings and precautions for use in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
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WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Severe Neutropenia

Background

FAZACLO can cause neutropenia (a low absolute neutrophil count [ANC]), defined as a reduction below pre-treatment normal levels of blood neutrophils. The ANC is usually available as a component of the complete blood count (CBC), including differential, and is more relevant to drug-induced neutropenia than is the white blood cell (WBC) count. The ANC may also be calculated using the following formula: ANC equals the Total WBC count multiplied by the total percentage of neutrophils obtained from the differential (neutrophil “segs” plus neutrophil “bands”). Other granulocytes (basophils and eosinophils) contribute minimally to neutropenia and their measurement is not necessary. Neutropenia may be mild, moderate, or severe (see Tables 2 and 3). To improve and standardize understanding, “severe neutropenia” replaces the previous terms severe leukopenia, severe granulocytopenia, or agranulocytosis.

Severe neutropenia, ANC less than ( < ) 500/μL, occurs in a small percentage of patients taking FAZACLO and is associated with an increase in the risk of serious and potentially fatal infections. Risk of neutropenia appears greatest during the first 18 weeks on treatment and then declines. The mechanism by which FAZACLO causes neutropenia is unknown and is not dose-dependent.

Two separate management algorithms are provided below, the first for patients in the general population, and the second for patients identified to have baseline neutropenia.

FAZACLO Treatment and Monitoring in the General Patient Population (see Table 2)

Obtain a CBC, including the ANC value, prior to initiating treatment with FAZACLO to ensure the presence of a normal baseline neutrophil count (equal to or greater than 1500/μL) and to permit later comparisons. Patients in the general population with an ANC equal to or greater than ( ≥ )1500/μL are considered within normal range (Table 2) and are eligible to initiate treatment. Weekly ANC monitoring is required for all patients during the first 6 months of treatment. If a patient's ANC remains equal to or greater than 1500/μL for the first 6 months of treatment, monitoring frequency may be reduced to every 2 weeks for the next 6 months. If the ANC remains equal to or greater than 1500/μL for the second 6 months of continuous therapy, ANC monitoring frequency may be reduced to once every 4 weeks thereafter.

Table 2: FAZACLO Treatment Recommendations Based on Absolute Neutrophil Count (ANC) Monitoring for the General Patient Population

ANC Level FAZACLO Treatment Recommendations ANC Monitoring
Normal range ( ≥ 1500/μL)
  • Initiate treatment
  • If treatment interrupted:
    • < 30 days, continue monitoring as before
    • ≥ 30 days, monitor as if new patient
  • Weekly from initiation to 6 months
  • Every 2 weeks from 6 to 12 months
  • Monthly after 12 months
  • Discontinuation for reasons other than neutropenia
  • See DOSAGE AND ADMINISTRATION, Maintenance Treatment
Mild Neutropenia (1000 to 1499/μL)*
  • Continue treatment
  • Three times weekly until ANC ≥ 1500/μL
  • Once ANC ≥ 1500/μL, return to patient’s last “Normal Range” ANC monitoring interval**
Moderate Neutropenia (500 to 999/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Resume treatment once ANC > 1000/μL
  • Daily until ANC ≥ 1000/μL, then
  • Three times weekly until ANC ≥ 1500/μL
  • Once ANC ≥ 1500/μL, check ANC weekly for 4 weeks, then return to patient’s last “Normal Range” ANC monitoring interval**
Severe Neutropenia (less than 500/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Do not rechallenge unless prescriber determines benefits outweigh risks
  • Daily until ANC ≥ 1000/μL, then
  • Three times weekly until ANC ≥ 1500/μL
  • If patient rechallenged, resume treatment as a new patient under “Normal Range” monitoring once ANC ≥ 1500/μL
* Confirm all initial reports of ANC less than 1500/μL with a repeat ANC measurement within 24 hours
** If clinically appropriate

FAZACLO Treatment and Monitoring in Patients with Benign Ethnic Neutropenia (see Table 3)

Benign ethnic neutropenia (BEN) is a condition observed in certain ethnic groups whose average ANC values are lower than “standard” laboratory ranges for neutrophils. It is most commonly observed in individuals of African descent (approximate prevalence of 25-50%), some Middle Eastern ethnic groups, and in other non-Caucasian ethnic groups with darker skin. BEN is more common in men. Patients with BEN have normal hematopoietic stem-cell number and myeloid maturation, are healthy, and do not suffer from repeated or severe infections. They are not at increased risk for developing FAZACLO-induced neutropenia. Additional evaluation may be needed to determine if baseline neutropenia is due to BEN. Consider hematology consultation before initiating or during FAZACLO treatment as necessary.

Patients with BEN require a different ANC algorithm for FAZACLO management due to their lower baseline ANC levels. Table 3 provides guidelines for managing FAZACLO treatment and ANC monitoring in patients with BEN.

Table 3: Patients with Benign Ethnic Neutropenia (BEN); FAZACLO Treatment Recommendations Based on Absolute Neutrophil Count (ANC) Monitoring

ANC Level Treatment Recommendations ANC Monitoring
Normal BEN Range (Established ANC baseline > 1000/μL )
  • Obtain at least two baseline ANC levels before initiating treatment
  • If treatment interrupted
    • < 30 days, continue monitoring as before
    • ≥ 30 days, monitor as if new patient
  • Weekly from initiation to 6 months
  • Every 2 weeks from 6 to 12 months
  • Monthly after 12 months
  • Discontinuation of treatment for reasons other than neutropenia
  • See DOSAGE AND ADMINISTRATION, Maintenance Treatment
BEN Neutropenia (500 to 999/μL)*
  • Recommend hematology consultation
  • Continue treatment

 

  • Three times weekly until ANC ≥ 1000/μL or ≥ patient’s known baseline
  • Once ANC ≥ 1000/μL or at patient’s known baseline, check ANC weekly for 4 weeks, then return to patient’s last “Normal BEN Range” ANC monitoring interval.**
BEN Severe Neutropenia (less than 500/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Do not rechallenge unless prescriber determines benefits outweigh risks
  • Daily until ANC ≥ 500/μL, then
  • Three times weekly until ANC ≥ patient’s baseline
  • If patient rechallenged, resume treatment as a new patient under “Normal Range” monitoring once ANC ≥ 1000/μL or at patient’s baseline
* Confirm all initial reports of ANC less than 1500/μL with a repeat ANC measurement within 24 hours
** If clinically appropriate

General Guidelines for Management of All Patients with Fever or with Neutropenia
  • Fever: Interrupt FAZACLO as a precautionary measure in any patient who develops fever, defined as a temperature of 38.5°C [101.3°F] or greater, and obtain an ANC level. Fever is often the first sign of neutropenic infection.
  • ANC less than 1000/μL: If fever occurs in any patient with an ANC less than 1000/μL, initiate appropriate workup and treatment for infection and refer to Tables 2 or 3 for management.
  • Consider hematology consultation.
  • See Neuroleptic Malignant Syndrome (NMS) and Fever under WARNINGS AND PRECAUTIONS and Instructions for Patients, under PATIENT INFORMATION).
Rechallenge after an ANC less than 500/μL (Severe Neutropenia)

For some patients who experience severe FAZACLO-related neutropenia, the risk of serious psychiatric illness from discontinuing FAZACLO treatment may be greater than the risk of rechallenge (e.g., patients with severe schizophrenic illness who have no treatment options other than FAZACLO). A hematology consultation may be useful in deciding to rechallenge a patient. In general, however, do not rechallenge patients who develop severe neutropenia with FAZACLO or a clozapine product.

If a patient will be rechallenged, the clinician should consider thresholds provided in Tables 2 and 3, the patient's medical and psychiatric history, a discussion with the patient and his/her caregiver about the benefits and risks of FAZACLO rechallenge, and the severity and characteristics of the neutropenic episode.

Using FAZACLO with Other Drugs Associated with Neutropenia

It is unclear if concurrent use of other drugs known to cause neutropenia increases the risk or severity of FAZACLO-induced neutropenia. There is no strong scientific rationale to avoid FAZACLO treatment in patients concurrently treated with these drugs. If FAZACLO is used concurrently with an agent known to cause neutropenia (e.g., some chemotherapeutic agents), consider monitoring patients more closely than the treatment guidelines provided in Tables 2 and 3. Consult with the treating oncologist in patients receiving concomitant chemotherapy.

Clozapine REMS Program

FAZACLO is only available through a restricted program under a REMS called the Clozapine REMS Program because of the risk of severe neutropenia.

Notable requirements of the Clozapine REMS Program include:

  • Healthcare professionals who prescribe FAZACLO must be certified with the program by enrolling and completing training.
  • Patients who receive FAZACLO must be enrolled in the program and comply with the ANC testing and monitoring requirements.
  • Pharmacies dispensing FAZACLO must be certified with the program by enrolling and completing training and must only dispense to patients who are eligible to receive FAZACLO.

Further information is available at www.clozapinerems.com or 1-844-267-8678.

Orthostatic Hypotension, Bradycardia, And Syncope

Hypotension, bradycardia, syncope, and cardiac arrest have occurred with clozapine treatment. The risk is highest during the initial titration period, particularly with rapid dose-escalation. These reactions can occur with the first dose, at doses as low as 12.5 mg. These reactions can be fatal. The syndrome is consistent with neurally mediated reflex bradycardia (NMRB).

Treatment must begin at a maximum dose of 12.5 mg once daily or twice daily. The total daily dose can be increased in increments of 25 mg to 50 mg per day, if well-tolerated, to a target dose of 300 mg to 450 mg per day (administered in divided doses) by the end of 2 weeks. Subsequently, the dose can be increased weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. Use cautious titration and a divided dosage schedule to minimize the risk of serious cardiovascular reactions. Consider reducing the dose if hypotension occurs. When restarting patients who have had even a brief interval off FAZACLO (i.e., 2 days or more since the last dose), re-initiate treatment at 12.5 mg once daily or twice daily.

Use FAZACLO cautiously in patients with cardiovascular disease (history of myocardial infarction or ischemia, heart failure, or conduction abnormalities), cerebrovascular disease, and conditions which would predispose patients to hypotension (e.g., concomitant use of antihypertensives, dehydration and hypovolemia).

Seizures

Seizure has been estimated to occur in association with clozapine use at a cumulative incidence at one year of approximately 5%, based on the occurrence of one or more seizures in 61 of 1743 patients exposed to clozapine during its clinical testing prior to domestic marketing (i.e., a crude rate of 3.5%). The risk of seizure is dose-related. Initiate treatment with a low dose (12.5 mg), titrate slowly, and use divided dosing.

Use caution when administering FAZACLO to patients with a history of seizures or other predisposing risk factors for seizure (e.g., head trauma or other CNS pathology, use of medications that lower the seizure threshold, or alcohol abuse). Because of the substantial risk of seizure associated with FAZACLO use, caution patients about engaging in any activity where sudden loss of consciousness could cause serious risk to themselves or others (e.g., driving an automobile, operating complex machinery, swimming, climbing).

Myocarditis And Cardiomyopathy

Myocarditis and cardiomyopathy have occurred with the use of clozapine. These reactions can be fatal. Discontinue FAZACLO and obtain a cardiac evaluation upon suspicion of myocarditis or cardiomyopathy. Generally, patients with a history of clozapine-associated myocarditis or cardiomyopathy should not be rechallenged with FAZACLO. However, if the benefit of FAZACLO treatment is judged to outweigh the potential risks of recurrent myocarditis or cardiomyopathy, the clinician may consider rechallenge with FAZACLO in consultation with a cardiologist, after a complete cardiac evaluation, and under close monitoring.

Consider the possibility of myocarditis or cardiomyopathy in patients receiving FAZACLO who present with chest pain, dyspnea, persistent tachycardia at rest, palpitations, fever, flu-like symptoms, hypotension, other signs or symptoms of heart failure, or electrocardiographic findings (low voltages, ST-T abnormalities, arrhythmias, right axis deviation, and poor R wave progression). Myocarditis most frequently presents within the first two months of clozapine treatment. Symptoms of cardiomyopathy generally occur later than clozapine-associated myocarditis and usually after 8 weeks of treatment. However, myocarditis and cardiomyopathy can occur at any period during treatment with FAZACLO. It is common for nonspecific flu-like symptoms such as malaise, myalgia, pleuritic chest pain, and low-grade fevers to precede more overt signs of heart failure. Typical laboratory findings include elevated troponin I or T, elevated creatinine kinase-MB, peripheral eosinophilia, and elevated C-reactive protein (CRP). Chest roentgenogram may demonstrate cardiac silhouette enlargement, and cardiac imaging (echocardiogram, radionucleotide studies, or cardiac catheterization) may reveal evidence of left ventricular dysfunction.

Increased Mortality In Elderly Patients With Dementia-Related Psychosis

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of 17 placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.5%, compared to a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality in this population. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patients is not clear. FAZACLO is not approved for the treatment of patients with dementia-related psychosis.

Eosinophilia

Eosinophilia, defined as a blood eosinophil count of greater than 700/μL, has occurred with clozapine treatment. In clinical trials, approximately 1% of patients developed eosinophilia. Clozapine-related eosinophilia usually occurs during the first month of treatment. In some patients, it has been associated with myocarditis, pancreatitis, hepatitis, colitis, and nephritis. Such organ involvement could be consistent with a drug reaction with eosinophilia and systemic symptoms syndrome (DRESS), also known as drug induced hypersensitivity syndrome (DIHS).

If eosinophilia develops during FAZACLO treatment, evaluate promptly for signs and symptoms of systemic reactions, such as rash or other allergic symptoms, myocarditis, or other organ-specific disease associated with eosinophilia. If clozapine-related systemic disease is suspected, discontinue FAZACLO immediately.

If a cause of eosinophilia unrelated to clozapine is identified (e.g., asthma, allergies, collagen vascular disease, parasitic infections, and specific neoplasms), treat the underlying cause and continue FAZACLO.

Clozapine-related eosinophilia has also occurred in the absence of organ involvement and can resolve without intervention. There are reports of successful rechallenge after discontinuation of clozapine, without recurrence of eosinophilia. In the absence of organ involvement, continue FAZACLO under careful monitoring. If the total eosinophil count continues to increase over several weeks in the absence of systemic disease, the decision to interrupt FAZACLO therapy and rechallenge after the eosinophil count decreases should be based on the overall clinical assessment, in consultation with an internist or hematologist.

QT Interval Prolongation

QT prolongation, Torsades de Pointes and other life-threatening ventricular arrhythmias, cardiac arrest, and sudden death have occurred with clozapine treatment. When prescribing FAZACLO, consider the presence of additional risk factors for QT prolongation and serious cardiovascular reactions. Conditions that increase these risks include the following: history of QT prolongation, long QT syndrome, family history of long QT syndrome or sudden cardiac death, significant cardiac arrhythmia, recent myocardial infarction, uncompensated heart failure, treatment with other medications that cause QT prolongation, treatment with medications that inhibit the metabolism of FAZACLO, and electrolyte abnormalities.

Prior to initiating treatment with FAZACLO, perform a careful physical examination, medical history, and concomitant medication history. Consider obtaining a baseline ECG and serum chemistry panel. Correct electrolyte abnormalities. Discontinue FAZACLO if the QTc interval exceeds 500 msec. If patients experience symptoms consistent with Torsades de Pointes or other arrhythmias (e.g., syncope, presyncope, dizziness, or palpitations), obtain a cardiac evaluation and discontinue FAZACLO.

Use caution when administering concomitant medications that prolong the QT interval or inhibit the metabolism of FAZACLO. Drugs that cause QT prolongation include: specific antipsychotics (e.g., ziprasidone, iloperidone, chlorpromazine, thioridazine, mesoridazine, droperidol, pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmic medications (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus). FAZACLO is primarily metabolized by CYP isoenzymes 1A2, 2D6, and 3A4. Concomitant treatment with inhibitors of these enzymes can increase the concentration of FAZACLO.

Hypokalemia and hypomagnesemia increase the risk of QT prolongation. Hypokalemia can result from diuretic therapy, diarrhea, and other causes. Use caution when treating patients at risk for significant electrolyte disturbance, particularly hypokalemia. Obtain baseline measurements of serum potassium and magnesium levels, and periodically monitor electrolytes. Correct electrolyte abnormalities before initiating treatment with FAZACLO.

Metabolic Changes

Atypical antipsychotic drugs, including FAZACLO, have been associated with metabolic changes that can increase cardiovascular and cerebrovascular risk. These metabolic changes include hyperglycemia, dyslipidemia, and body weight gain. While atypical antipsychotic drugs may produce some metabolic changes, each drug in the class has its own specific risk profile.

Hyperglycemia and Diabetes Mellitus

Hyperglycemia, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, has been reported in patients treated with atypical antipsychotics including FAZACLO. Assessment of the relationship between atypical antipsychotic use and glucose abnormalities is complicated by the possibility of an increased background risk of diabetes mellitus in patients with schizophrenia and the increasing incidence of diabetes mellitus in the general population. Given these confounders, the relationship between atypical antipsychotic use and hyperglycemia-related adverse reactions is not completely understood. However, epidemiological studies suggest an increased risk of treatment-emergent, hyperglycemia-related adverse reactions in patients treated with the atypical antipsychotics. Precise risk estimates for hyperglycemia-related adverse reactions in patients treated with atypical antipsychotics are not available.

Patients with an established diagnosis of diabetes mellitus who are started on FAZACLO should be monitored regularly for worsening of glucose control. Patients with risk factors for diabetes mellitus (e.g., obesity, family history of diabetes) who are starting treatment with atypical antipsychotics should undergo fasting blood glucose testing at the beginning of treatment and periodically during treatment. Any patient treated with atypical antipsychotics should be monitored for symptoms of hyperglycemia including polydipsia, polyuria, polyphagia, and weakness. Patients who develop symptoms of hyperglycemia during treatment with atypical antipsychotics should undergo fasting blood glucose testing. In some cases, hyperglycemia has resolved when the atypical antipsychotic was discontinued; however, some patients required continuation of anti-diabetic treatment despite discontinuation of the suspect drug.

In a pooled data analysis of 8 studies in adult subjects with schizophrenia, the mean changes in fasting glucose concentration in the clozapine and chlorpromazine groups were +11 mg/dL and +4 mg/dL respectively. A higher proportion of the clozapine group demonstrated categorical increases from baseline in fasting glucose concentrations, compared to the chlorpromazine group (Table 4). The clozapine doses were 100-900 mg per day (mean modal dose: 512 mg per day). The maximum chlorpromazine dose was 1800 mg per day (mean modal dose: 1029 mg per day). The median duration of exposure was 42 days for clozapine and chlorpromazine.

Table 4: Categorical Changes in Fasting Glucose Level in Studies in Adult Subjects with Schizophrenia

Laboratory Parameter Category Change (at least once) from Baseline Treatment Arm N n (%)
Fasting Glucose Normal ( < 100 mg/dL) to High ( ≥ 126 mg/dL) Clozapine 198 53 (27)
Chlorpromazine 135 14 (10)
Borderline (100 to 125 mg/dL) to High ( ≥ 126 mg/dL) Clozapine 57 24 (42)
Chlorpromazine 43 12 (28)

Dyslipidemia

Undesirable alterations in lipids have occurred in patients treated with atypical antipsychotics, including FAZACLO. Clinical monitoring, including baseline and periodic follow-up lipid evaluations in patients using FAZACLO, is recommended.

In a pooled data analysis of 10 studies in adult subjects with schizophrenia, clozapine treatment was associated with increases in serum total cholesterol. No data were collected on LDL and HDL cholesterol. The mean increase in total cholesterol was 13 mg/dL in the clozapine group and 15 mg/dL in the chlorpromazine group. In a pooled data analysis of 2 studies in adult subjects with schizophrenia, clozapine treatment was associated with increases in fasting serum triglyceride. The mean increase in fasting triglyceride was 71 mg/dL (54%) in the clozapine group and 39 mg/dL (35%) in the chlorpromazine group (Table 5). In addition, clozapine treatment was associated with categorical increases in serum total cholesterol and triglyceride, as illustrated in Table 6. The proportion of patients with categorical increases in total cholesterol or fasting triglyceride increased with the duration of exposure. The median duration of clozapine and chlorpromazine exposure was 45 days and 38 days, respectively. The clozapine dose range was 100 mg to 900 mg daily; the maximum chlorpromazine dose was 1800 mg daily.

Table 5: Mean Changes in Total Cholesterol and Triglyceride Concentration in Studies in Adult Subjects with Schizophrenia

Treatment Arm Baseline Total Cholesterol Concentration (mg/dL) Change from Baseline mg/dL (%)
Clozapine (N=334) 184 +13 (7)
Chlorpromazine (N=185) 182 +15 (8)
  Baseline Triglyceride Concentration (mg/dL) Change from Baseline mg/dL (%)
Clozapine (N=6) 130 +71 (54)
Chlorpromazine (N=7) 110 +39 (35)

Table 6: Categorical Changes in Lipid Concentrations in Studies in Adult Subjects with Schizophrenia

Laboratory Parameter Category Change (at least once) from Baseline Treatment Arm N n (%)
Total Cholesterol (random or fasting) Increase by ≥ 40 mg/dL Clozapine 334 111 (33)
Chlorpromazine 185 46 (25)
Normal ( < 200 mg/dL) to High ( ≥ 240 mg/dL) Clozapine 222 18 (8)
Chlorpromazine 132 3 (2)
Borderline (200 - 239 mg/dL) to High ( ≥ 240 mg/dL) Clozapine 79 30 (38)
Chlorpromazine 34 14 (41)
Triglycerides (fasting) Increase by ≥ 50 mg/dL Clozapine 6 3 (50)
Chlorpromazine 7 3 (43)
Normal ( < 150 mg/dL) to High ( ≥ 200 mg/dL) Clozapine 4 0 (0)
Chlorpromazine 6 2 (33)
Borderline ( ≥ 150 mg/dL and < 200 mg/dL) to High ( ≥ 200 mg/dL) Clozapine 1 1 (100)
Chlorpromazine 1 0 (0)

Weight Gain

Weight gain has occurred with the use of antipsychotics, including FAZACLO. Monitor weight during treatment with FAZACLO. Table 7 summarizes the data on weight gain by the duration of exposure pooled from 11 studies with clozapine and active comparators. The median duration of exposure was 609, 728, and 42 days, in the clozapine, olanzapine, and chlorpromazine group, respectively.

Table 7: Mean Change in Body Weight (kg) by duration of exposure from studies in adult subjects with schizophrenia

Metabolic Parameter Exposure Duration Clozapine
(N=669)
Olanzapine
(N=442)
Chlorpromazine
N=155)
n Mean n Mean n Mean
Weight change from baseline 2 weeks (Day 11 - 17) 6 +0.9 3 +0.7 2 -0.5
4 weeks (Day 21 - 35) 23 +0.7 8 +0.8 17 +0.6
8 weeks (Day 49 - 63) 12 + 1.9 13 + 1.8 16 +0.9
12 weeks (Day 70 - 98) 17 +2.8 5 +3.1 0 0
24 weeks (Day 154 - 182) 42 -0.6 12 +5.7 0 0
48 weeks (Day 322 - 350) 3 +3.7 3 +13.7 0 0

Table 8 summarizes pooled data from 11 studies in

WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Severe Neutropenia

Background

Klozapol can cause neutropenia (a low absolute neutrophil count [ANC]), defined as a reduction below pre-treatment normal levels of blood neutrophils. The ANC is usually available as a component of the complete blood count (CBC), including differential, and is more relevant to drug-induced neutropenia than is the white blood cell (WBC) count. The ANC may also be calculated using the following formula: ANC equals the Total WBC count multiplied by the total percentage of neutrophils obtained from the differential (neutrophil “segs” plus neutrophil “bands”). Other granulocytes (basophils and eosinophils) contribute minimally to neutropenia and their measurement is not necessary. Neutropenia may be mild, moderate, or severe (see Tables 2 and 3). To improve and standardize understanding, “severe neutropenia” replaces the previous terms severe leukopenia, severe granulocytopenia, or agranulocytosis.

Severe neutropenia, ANC less than ( < ) 500/μL, occurs in a small percentage of patients taking Klozapol and is associated with an increase in the risk of serious and potentially fatal infections. Risk of neutropenia appears greatest during the first 18 weeks on treatment and then declines. The mechanism by which Klozapol causes neutropenia is unknown and is not dose-dependent.

Two separate management algorithms are provided below, the first for patients in the general population, and the second for patients identified to have baseline neutropenia.

Klozapol Treatment and Monitoring in the General Patient Population (see Table 2)

Obtain a CBC, including the ANC value, prior to initiating treatment with Klozapol to ensure the presence of a normal baseline neutrophil count (equal to or greater than 1500/μL) and to permit later comparisons. Patients in the general population with an ANC equal to or greater than ( ≥ )1500/μL are considered within normal range (Table 2) and are eligible to initiate treatment. Weekly ANC monitoring is required for all patients during the first 6 months of treatment. If a patient's ANC remains equal to or greater than 1500/μL for the first 6 months of treatment, monitoring frequency may be reduced to every 2 weeks for the next 6 months. If the ANC remains equal to or greater than 1500/μL for the second 6 months of continuous therapy, ANC monitoring frequency may be reduced to once every 4 weeks thereafter.

Table 2: Klozapol Treatment Recommendations Based on Absolute Neutrophil Count (ANC) Monitoring for the General Patient Population

ANC Level Klozapol Treatment Recommendations ANC Monitoring
Normal range ( ≥ 1500/μL)
  • Initiate treatment
  • If treatment interrupted:
    • < 30 days, continue monitoring as before
    • ≥ 30 days, monitor as if new patient
  • Weekly from initiation to 6 months
  • Every 2 weeks from 6 to 12 months
  • Monthly after 12 months
  • Discontinuation for reasons other than neutropenia
  • See DOSAGE AND ADMINISTRATION, Maintenance Treatment
Mild Neutropenia (1000 to 1499/μL)*
  • Continue treatment
  • Three times weekly until ANC ≥ 1500/μL
  • Once ANC ≥ 1500/μL, return to patient’s last “Normal Range” ANC monitoring interval**
Moderate Neutropenia (500 to 999/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Resume treatment once ANC > 1000/μL
  • Daily until ANC ≥ 1000/μL, then
  • Three times weekly until ANC ≥ 1500/μL
  • Once ANC ≥ 1500/μL, check ANC weekly for 4 weeks, then return to patient’s last “Normal Range” ANC monitoring interval**
Severe Neutropenia (less than 500/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Do not rechallenge unless prescriber determines benefits outweigh risks
  • Daily until ANC ≥ 1000/μL, then
  • Three times weekly until ANC ≥ 1500/μL
  • If patient rechallenged, resume treatment as a new patient under “Normal Range” monitoring once ANC ≥ 1500/μL
* Confirm all initial reports of ANC less than 1500/μL with a repeat ANC measurement within 24 hours
** If clinically appropriate

Klozapol Treatment and Monitoring in Patients with Benign Ethnic Neutropenia (see Table 3)

Benign ethnic neutropenia (BEN) is a condition observed in certain ethnic groups whose average ANC values are lower than “standard” laboratory ranges for neutrophils. It is most commonly observed in individuals of African descent (approximate prevalence of 25-50%), some Middle Eastern ethnic groups, and in other non-Caucasian ethnic groups with darker skin. BEN is more common in men. Patients with BEN have normal hematopoietic stem-cell number and myeloid maturation, are healthy, and do not suffer from repeated or severe infections. They are not at increased risk for developing Klozapol-induced neutropenia. Additional evaluation may be needed to determine if baseline neutropenia is due to BEN. Consider hematology consultation before initiating or during Klozapol treatment as necessary.

Patients with BEN require a different ANC algorithm for Klozapol management due to their lower baseline ANC levels. Table 3 provides guidelines for managing Klozapol treatment and ANC monitoring in patients with BEN.

Table 3: Patients with Benign Ethnic Neutropenia (BEN); Klozapol Treatment Recommendations Based on Absolute Neutrophil Count (ANC) Monitoring

ANC Level Treatment Recommendations ANC Monitoring
Normal BEN Range (Established ANC baseline > 1000/μL )
  • Obtain at least two baseline ANC levels before initiating treatment
  • If treatment interrupted
    • < 30 days, continue monitoring as before
    • ≥ 30 days, monitor as if new patient
  • Weekly from initiation to 6 months
  • Every 2 weeks from 6 to 12 months
  • Monthly after 12 months
  • Discontinuation of treatment for reasons other than neutropenia
  • See DOSAGE AND ADMINISTRATION, Maintenance Treatment
BEN Neutropenia (500 to 999/μL)*
  • Recommend hematology consultation
  • Continue treatment

 

  • Three times weekly until ANC ≥ 1000/μL or ≥ patient’s known baseline
  • Once ANC ≥ 1000/μL or at patient’s known baseline, check ANC weekly for 4 weeks, then return to patient’s last “Normal BEN Range” ANC monitoring interval.**
BEN Severe Neutropenia (less than 500/μL)*
  • Recommend hematology consultation
  • Interrupt treatment for suspected clozapine-induced neutropenia
  • Do not rechallenge unless prescriber determines benefits outweigh risks
  • Daily until ANC ≥ 500/μL, then
  • Three times weekly until ANC ≥ patient’s baseline
  • If patient rechallenged, resume treatment as a new patient under “Normal Range” monitoring once ANC ≥ 1000/μL or at patient’s baseline
* Confirm all initial reports of ANC less than 1500/μL with a repeat ANC measurement within 24 hours
** If clinically appropriate

General Guidelines for Management of All Patients with Fever or with Neutropenia
  • Fever: Interrupt Klozapol as a precautionary measure in any patient who develops fever, defined as a temperature of 38.5°C [101.3°F] or greater, and obtain an ANC level. Fever is often the first sign of neutropenic infection.
  • ANC less than 1000/μL: If fever occurs in any patient with an ANC less than 1000/μL, initiate appropriate workup and treatment for infection and refer to Tables 2 or 3 for management.
  • Consider hematology consultation.
  • See Neuroleptic Malignant Syndrome (NMS) and Fever under WARNINGS AND PRECAUTIONS and Instructions for Patients, under PATIENT INFORMATION).
Rechallenge after an ANC less than 500/μL (Severe Neutropenia)

For some patients who experience severe Klozapol-related neutropenia, the risk of serious psychiatric illness from discontinuing Klozapol treatment may be greater than the risk of rechallenge (e.g., patients with severe schizophrenic illness who have no treatment options other than Klozapol). A hematology consultation may be useful in deciding to rechallenge a patient. In general, however, do not rechallenge patients who develop severe neutropenia with Klozapol or a clozapine product.

If a patient will be rechallenged, the clinician should consider thresholds provided in Tables 2 and 3, the patient's medical and psychiatric history, a discussion with the patient and his/her caregiver about the benefits and risks of Klozapol rechallenge, and the severity and characteristics of the neutropenic episode.

Using Klozapol with Other Drugs Associated with Neutropenia

It is unclear if concurrent use of other drugs known to cause neutropenia increases the risk or severity of Klozapol-induced neutropenia. There is no strong scientific rationale to avoid Klozapol treatment in patients concurrently treated with these drugs. If Klozapol is used concurrently with an agent known to cause neutropenia (e.g., some chemotherapeutic agents), consider monitoring patients more closely than the treatment guidelines provided in Tables 2 and 3. Consult with the treating oncologist in patients receiving concomitant chemotherapy.

Clozapine REMS Program

Klozapol is only available through a restricted program under a REMS called the Clozapine REMS Program because of the risk of severe neutropenia.

Notable requirements of the Clozapine REMS Program include:

  • Healthcare professionals who prescribe Klozapol must be certified with the program by enrolling and completing training.
  • Patients who receive Klozapol must be enrolled in the program and comply with the ANC testing and monitoring requirements.
  • Pharmacies dispensing Klozapol must be certified with the program by enrolling and completing training and must only dispense to patients who are eligible to receive Klozapol.

Further information is available at www.clozapinerems.com or 1-844-267-8678.

Orthostatic Hypotension, Bradycardia, And Syncope

Hypotension, bradycardia, syncope, and cardiac arrest have occurred with clozapine treatment. The risk is highest during the initial titration period, particularly with rapid dose-escalation. These reactions can occur with the first dose, at doses as low as 12.5 mg. These reactions can be fatal. The syndrome is consistent with neurally mediated reflex bradycardia (NMRB).

Treatment must begin at a maximum dose of 12.5 mg once daily or twice daily. The total daily dose can be increased in increments of 25 mg to 50 mg per day, if well-tolerated, to a target dose of 300 mg to 450 mg per day (administered in divided doses) by the end of 2 weeks. Subsequently, the dose can be increased weekly or twice weekly, in increments of up to 100 mg. The maximum dose is 900 mg per day. Use cautious titration and a divided dosage schedule to minimize the risk of serious cardiovascular reactions. Consider reducing the dose if hypotension occurs. When restarting patients who have had even a brief interval off Klozapol (i.e., 2 days or more since the last dose), re-initiate treatment at 12.5 mg once daily or twice daily.

Use Klozapol cautiously in patients with cardiovascular disease (history of myocardial infarction or ischemia, heart failure, or conduction abnormalities), cerebrovascular disease, and conditions which would predispose patients to hypotension (e.g., concomitant use of antihypertensives, dehydration and hypovolemia).

Seizures

Seizure has been estimated to occur in association with clozapine use at a cumulative incidence at one year of approximately 5%, based on the occurrence of one or more seizures in 61 of 1743 patients exposed to clozapine during its clinical testing prior to domestic marketing (i.e., a crude rate of 3.5%). The risk of seizure is dose-related. Initiate treatment with a low dose (12.5 mg), titrate slowly, and use divided dosing.

Use caution when administering Klozapol to patients with a history of seizures or other predisposing risk factors for seizure (e.g., head trauma or other CNS pathology, use of medications that lower the seizure threshold, or alcohol abuse). Because of the substantial risk of seizure associated with Klozapol use, caution patients about engaging in any activity where sudden loss of consciousness could cause serious risk to themselves or others (e.g., driving an automobile, operating complex machinery, swimming, climbing).

Myocarditis And Cardiomyopathy

Myocarditis and cardiomyopathy have occurred with the use of clozapine. These reactions can be fatal. Discontinue Klozapol and obtain a cardiac evaluation upon suspicion of myocarditis or cardiomyopathy. Generally, patients with a history of clozapine-associated myocarditis or cardiomyopathy should not be rechallenged with Klozapol. However, if the benefit of Klozapol treatment is judged to outweigh the potential risks of recurrent myocarditis or cardiomyopathy, the clinician may consider rechallenge with Klozapol in consultation with a cardiologist, after a complete cardiac evaluation, and under close monitoring.

Consider the possibility of myocarditis or cardiomyopathy in patients receiving Klozapol who present with chest pain, dyspnea, persistent tachycardia at rest, palpitations, fever, flu-like symptoms, hypotension, other signs or symptoms of heart failure, or electrocardiographic findings (low voltages, ST-T abnormalities, arrhythmias, right axis deviation, and poor R wave progression). Myocarditis most frequently presents within the first two months of clozapine treatment. Symptoms of cardiomyopathy generally occur later than clozapine-associated myocarditis and usually after 8 weeks of treatment. However, myocarditis and cardiomyopathy can occur at any period during treatment with Klozapol. It is common for nonspecific flu-like symptoms such as malaise, myalgia, pleuritic chest pain, and low-grade fevers to precede more overt signs of heart failure. Typical laboratory findings include elevated troponin I or T, elevated creatinine kinase-MB, peripheral eosinophilia, and elevated C-reactive protein (CRP). Chest roentgenogram may demonstrate cardiac silhouette enlargement, and cardiac imaging (echocardiogram, radionucleotide studies, or cardiac catheterization) may reveal evidence of left ventricular dysfunction.

Increased Mortality In Elderly Patients With Dementia-Related Psychosis

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of 17 placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.5%, compared to a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality in this population. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patients is not clear. Klozapol is not approved for the treatment of patients with dementia-related psychosis.

Eosinophilia

Eosinophilia, defined as a blood eosinophil count of greater than 700/μL, has occurred with clozapine treatment. In clinical trials, approximately 1% of patients developed eosinophilia. Clozapine-related eosinophilia usually occurs during the first month of treatment. In some patients, it has been associated with myocarditis, pancreatitis, hepatitis, colitis, and nephritis. Such organ involvement could be consistent with a drug reaction with eosinophilia and systemic symptoms syndrome (DRESS), also known as drug induced hypersensitivity syndrome (DIHS).

If eosinophilia develops during Klozapol treatment, evaluate promptly for signs and symptoms of systemic reactions, such as rash or other allergic symptoms, myocarditis, or other organ-specific disease associated with eosinophilia. If clozapine-related systemic disease is suspected, discontinue Klozapol immediately.

If a cause of eosinophilia unrelated to clozapine is identified (e.g., asthma, allergies, collagen vascular disease, parasitic infections, and specific neoplasms), treat the underlying cause and continue Klozapol.

Clozapine-related eosinophilia has also occurred in the absence of organ involvement and can resolve without intervention. There are reports of successful rechallenge after discontinuation of clozapine, without recurrence of eosinophilia. In the absence of organ involvement, continue Klozapol under careful monitoring. If the total eosinophil count continues to increase over several weeks in the absence of systemic disease, the decision to interrupt Klozapol therapy and rechallenge after the eosinophil count decreases should be based on the overall clinical assessment, in consultation with an internist or hematologist.

QT Interval Prolongation

QT prolongation, Torsades de Pointes and other life-threatening ventricular arrhythmias, cardiac arrest, and sudden death have occurred with clozapine treatment. When prescribing Klozapol, consider the presence of additional risk factors for QT prolongation and serious cardiovascular reactions. Conditions that increase these risks include the following: history of QT prolongation, long QT syndrome, family history of long QT syndrome or sudden cardiac death, significant cardiac arrhythmia, recent myocardial infarction, uncompensated heart failure, treatment with other medications that cause QT prolongation, treatment with medications that inhibit the metabolism of Klozapol, and electrolyte abnormalities.

Prior to initiating treatment with Klozapol, perform a careful physical examination, medical history, and concomitant medication history. Consider obtaining a baseline ECG and serum chemistry panel. Correct electrolyte abnormalities. Discontinue Klozapol if the QTc interval exceeds 500 msec. If patients experience symptoms consistent with Torsades de Pointes or other arrhythmias (e.g., syncope, presyncope, dizziness, or palpitations), obtain a cardiac evaluation and discontinue Klozapol.

Use caution when administering concomitant medications that prolong the QT interval or inhibit the metabolism of Klozapol. Drugs that cause QT prolongation include: specific antipsychotics (e.g., ziprasidone, iloperidone, chlorpromazine, thioridazine, mesoridazine, droperidol, pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmic medications (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus). Klozapol is primarily metabolized by CYP isoenzymes 1A2, 2D6, and 3A4. Concomitant treatment with inhibitors of these enzymes can increase the concentration of Klozapol.

Hypokalemia and hypomagnesemia increase the risk of QT prolongation. Hypokalemia can result from diuretic therapy, diarrhea, and other causes. Use caution when treating patients at risk for significant electrolyte disturbance, particularly hypokalemia. Obtain baseline measurements of serum potassium and magnesium levels, and periodically monitor electrolytes. Correct electrolyte abnormalities before initiating treatment with Klozapol.

Metabolic Changes

Atypical antipsychotic drugs, including Klozapol, have been associated with metabolic changes that can increase cardiovascular and cerebrovascular risk. These metabolic changes include hyperglycemia, dyslipidemia, and body weight gain. While atypical antipsychotic drugs may produce some metabolic changes, each drug in the class has its own specific risk profile.

Hyperglycemia and Diabetes Mellitus

Hyperglycemia, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, has been reported in patients treated with atypical antipsychotics including Klozapol. Assessment of the relationship between atypical antipsychotic use and glucose abnormalities is complicated by the possibility of an increased background risk of diabetes mellitus in patients with schizophrenia and the increasing incidence of diabetes mellitus in the general population. Given these confounders, the relationship between atypical antipsychotic use and hyperglycemia-related adverse reactions is not completely understood. However, epidemiological studies suggest an increased risk of treatment-emergent, hyperglycemia-related adverse reactions in patients treated with the atypical antipsychotics. Precise risk estimates for hyperglycemia-related adverse reactions in patients treated with atypical antipsychotics are not available.

Patients with an established diagnosis of diabetes mellitus who are started on Klozapol should be monitored regularly for worsening of glucose control. Patients with risk factors for diabetes mellitus (e.g., obesity, family history of diabetes) who are starting treatment with atypical antipsychotics should undergo fasting blood glucose testing at the beginning of treatment and periodically during treatment. Any patient treated with atypical antipsychotics should be monitored for symptoms of hyperglycemia including polydipsia, polyuria, polyphagia, and weakness. Patients who develop symptoms of hyperglycemia during treatment with atypical antipsychotics should undergo fasting blood glucose testing. In some cases, hyperglycemia has resolved when the atypical antipsychotic was discontinued; however, some patients required continuation of anti-diabetic treatment despite discontinuation of the suspect drug.

In a pooled data analysis of 8 studies in adult subjects with schizophrenia, the mean changes in fasting glucose concentration in the clozapine and chlorpromazine groups were +11 mg/dL and +4 mg/dL respectively. A higher proportion of the clozapine group demonstrated categorical increases from baseline in fasting glucose concentrations, compared to the chlorpromazine group (Table 4). The clozapine doses were 100-900 mg per day (mean modal dose: 512 mg per day). The maximum chlorpromazine dose was 1800 mg per day (mean modal dose: 1029 mg per day). The median duration of exposure was 42 days for clozapine and chlorpromazine.

Table 4: Categorical Changes in Fasting Glucose Level in Studies in Adult Subjects with Schizophrenia

Laboratory Parameter Category Change (at least once) from Baseline Treatment Arm N n (%)
Fasting Glucose Normal ( < 100 mg/dL) to High ( ≥ 126 mg/dL) Clozapine 198 53 (27)
Chlorpromazine 135 14 (10)
Borderline (100 to 125 mg/dL) to High ( ≥ 126 mg/dL) Clozapine 57 24 (42)
Chlorpromazine 43 12 (28)

Dyslipidemia

Undesirable alterations in lipids have occurred in patients treated with atypical antipsychotics, including Klozapol. Clinical monitoring, including baseline and periodic follow-up lipid evaluations in patients using Klozapol, is recommended.

In a pooled data analysis of 10 studies in adult subjects with schizophrenia, clozapine treatment was associated with increases in serum total cholesterol. No data were collected on LDL and HDL cholesterol. The mean increase in total cholesterol was 13 mg/dL in the clozapine group and 15 mg/dL in the chlorpromazine group. In a pooled data analysis of 2 studies in adult subjects with schizophrenia, clozapine treatment was associated with increases in fasting serum triglyceride. The mean increase in fasting triglyceride was 71 mg/dL (54%) in the clozapine group and 39 mg/dL (35%) in the chlorpromazine group (Table 5). In addition, clozapine treatment was associated with categorical increases in serum total cholesterol and triglyceride, as illustrated in Table 6. The proportion of patients with categorical increases in total cholesterol or fasting triglyceride increased with the duration of exposure. The median duration of clozapine and chlorpromazine exposure was 45 days and 38 days, respectively. The clozapine dose range was 100 mg to 900 mg daily; the maximum chlorpromazine dose was 1800 mg daily.

Table 5: Mean Changes in Total Cholesterol and Triglyceride Concentration in Studies in Adult Subjects with Schizophrenia

Treatment Arm Baseline Total Cholesterol Concentration (mg/dL) Change from Baseline mg/dL (%)
Clozapine (N=334) 184 +13 (7)
Chlorpromazine (N=185) 182 +15 (8)
  Baseline Triglyceride Concentration (mg/dL) Change from Baseline mg/dL (%)
Clozapine (N=6) 130 +71 (54)
Chlorpromazine (N=7) 110 +39 (35)

Table 6: Categorical Changes in Lipid Concentrations in Studies in Adult Subjects with Schizophrenia

Laboratory Parameter Category Change (at least once) from Baseline Treatment Arm N n (%)
Total Cholesterol (random or fasting) Increase by ≥ 40 mg/dL Clozapine 334 111 (33)
Chlorpromazine 185 46 (25)
Normal ( < 200 mg/dL) to High ( ≥ 240 mg/dL) Clozapine 222 18 (8)
Chlorpromazine 132 3 (2)
Borderline (200 - 239 mg/dL) to High ( ≥ 240 mg/dL) Clozapine 79 30 (38)
Chlorpromazine 34 14 (41)
Triglycerides (fasting) Increase by ≥ 50 mg/dL Clozapine 6 3 (50)
Chlorpromazine 7 3 (43)
Normal ( < 150 mg/dL) to High ( ≥ 200 mg/dL) Clozapine 4 0 (0)
Chlorpromazine 6 2 (33)
Borderline ( ≥ 150 mg/dL and < 200 mg/dL) to High ( ≥ 200 mg/dL) Clozapine 1 1 (100)
Chlorpromazine 1 0 (0)

Weight Gain

Weight gain has occurred with the use of antipsychotics, including Klozapol. Monitor weight during treatment with Klozapol. Table 7 summarizes the data on weight gain by the duration of exposure pooled from 11 studies with clozapine and active comparators. The median duration of exposure was 609, 728, and 42 days, in the clozapine, olanzapine, and chlorpromazine group, respectively.

Table 7: Mean Change in Body Weight (kg) by duration of exposure from studies in adult subjects with schizophrenia

Metabolic Parameter Exposure Duration Clozapine
(N=669)
Olanzapine
(N=442)
Chlorpromazine
N=155)
n Mean n Mean n Mean
Weight change from baseline 2 weeks (Day 11 - 17) 6 +0.9 3 +0.7 2 -0.5
4 weeks (Day 21 - 35) 23 +0.7 8 +0.8 17 +0.6
8 weeks (Day 49 - 63) 12 + 1.9 13 + 1.8 16 +0.9
12 weeks (Day 70 - 98) 17 +2.8 5 +3.1 0 0
24 weeks (Day 154 - 182) 42 -0.6 12 +5.7 0 0
48 weeks (Day 322 - 350) 3 +3.7 3 +13.7 0 0

Table 8 summarizes pooled data from 11 studies in

Undesirable effects

The information provided in Undesirable effects of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Undesirable effects in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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The following adverse reactions are discussed in more detail in other sections of the labeling:

  • Severe Neutropenia.
  • Orthostatic Hypotension, Bradycardia, and Syncope.
  • Seizures.
  • Myocarditis and Cardiomyopathy.
  • Increased Mortality in Elderly Patients with Dementia-Related Psychosis.
  • Eosinophilia.
  • QT Interval Prolongation.
  • Metabolic Changes (Hyperglycemia and Diabetes Mellitus, Dyslipidemia, and Weight Gain).
  • Neuroleptic Malignant Syndrome.
  • Fever.
  • Pulmonary Embolism.
  • Anticholinergic Toxicity.
  • Interference with Cognitive and Motor Performance.
  • Tardive Dyskinesia.
  • Patients with Phenylketonuria.
  • Cerebrovascular Adverse Reactions.
  • Recurrence of Psychosis and Cholinergic Rebound after Abrupt Discontinuation.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

The most commonly reported adverse reactions ( ≥ 5%) across clozapine clinical trials were: CNS reactions, including sedation, dizziness/vertigo, headache, and tremor; cardiovascular reactions, including tachycardia, hypotension, and syncope; autonomic nervous system reactions, including hypersalivation, sweating, dry mouth, and visual disturbances; gastrointestinal reactions, including constipation and nausea; and fever. Table 9 summarizes the most commonly reported adverse reactions ( ≥ 5%) in clozapine-treated patients (compared to chlorpromazine-treated patients) in the pivotal, 6-week, controlled trial in treatment-resistant schizophrenia.

Table 9: Common Adverse Reactions ( ≥ 5%) in the 6-Week, Randomized, Chlorpromazinecontrolled Trial in Treatment-Resistant Schizophrenia

Adverse Reaction Clozapine
(N=126) (%)
Chlorpromazine
(N=142) (%)
Sedation 21 13
Tachycardia 17 11
Constipation 16 12
Dizziness 14 16
Hypotension 13 38
Fever (hyperthermia) 13 4
Hypersalivation 13 1
Hypertension 12 5
Headache 10 10
Nausea/vomiting 10 12
Dry mouth 5 20

Table 10 summarizes the adverse reactions reported in clozapine-treated patients at a frequency of 2% or greater across all clozapine studies (excluding the 2-year InterSePT™ Study). These rates are not adjusted for duration of exposure.

Table 10: Adverse Reactions ( ≥ 2%) Reported in Clozapine-treated Patients (N=842) across all Clozapine Studies (excluding the 2-year InterSePT™ Study)

Body System
Adverse Reaction
Clozapine
N=842
Percentage of Patients
Central Nervous System
  Drowsiness/Sedation 39
  Dizziness/Vertigo 19
  Headache 7
  Tremor 6
  Syncope 6
  Disturbed Sleep/Nightmares 4
  Restlessness 4
  Hypokinesia/Akinesia 4
  Agitation 4
  Seizures (convulsions) 3†
  Rigidity 3
  Akathisia 3
  Confusion 3
  Fatigue 2
  Insomnia 2
Cardiovascular
  Tachycardia 25†
  Hypotension 9
  Hypertension 4
Gastrointestinal
  Constipation 14
  Nausea 5
  Abdominal Discomfort/Heartburn 4
  Nausea/Vomiting 3
  Vomiting 3
  Diarrhea 2
Urogenital
  Urinary Abnormalities 2
Autonomic Nervous System
  Salivation 31
  Sweating 6
  Dry Mouth 6
  Visual Disturbances 5
Skin
  Rash 2
Hemic/Lymphatic
  Leukopenia/Decreased WBC/Neutropenia   3
Miscellaneous
  Fever 5
  Weight Gain 4
† Rate based on population of approximately 1700 exposed during premarket clinical evaluation of clozapine.

Table 11 summarizes the most commonly reported adverse reactions ( ≥ 10% of the clozapine or olanzapine group) in the InterSePT™ Study. This was an adequate and well-controlled, two-year study evaluating the efficacy of clozapine relative to olanzapine in reducing the risk of suicidal behavior in patients with schizophrenia or schizoaffective disorder. The rates are not adjusted for duration of exposure.

Table 11: Incidence of Adverse Reactions in Patients Treated with Clozapine or Olanzapine in the InterSePT™ Study ( ≥ 10% in the clozapine or olanzapine group)

Adverse Reactions Clozapine
N=479 % Reporting
Olanzapine
N=477 % Reporting
Salivary hypersecretion 48% 6%
Somnolence 46% 25%
Weight increased 31% 56%
Dizziness (excluding vertigo) 27% 12%
Constipation 25% 10%
Insomnia 20% 33%
Nausea 17% 10%
Vomiting 17% 9%
Dyspepsia 14% 8%

Dystonia

Class effect: Symptoms of dystonia, prolonged abnormal contractions of muscle groups, may occur in susceptible individuals during the first few days of treatment. Dystonic symptoms include: spasm of the neck muscles, sometimes progressing to tightness of the throat, swallowing difficulty, difficulty breathing, and/or protrusion of the tongue. While these symptoms can occur at low doses, they occur more frequently and with greater severity with high potency and at higher doses of first generation antipsychotic drugs. An elevated risk of acute dystonia is observed in males and younger age groups.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of clozapine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Central Nervous System

Delirium, EEG abnormal, myoclonus, paresthesia, possible cataplexy, status epilepticus, obsessive compulsive symptoms, and post-discontinuation cholinergic rebound adverse reactions.

Cardiovascular System

Atrial or ventricular fibrillation, ventricular tachycardia, QT interval prolongation, Torsades de Pointes, myocardial infarction, cardiac arrest, and periorbital edema.

Endocrine System

Pseudopheochromocytoma.

Gastrointestinal System

Acute pancreatitis, dysphagia, salivary gland swelling.

Hepatobiliary System

Cholestasis, hepatitis, jaundice, hepatotoxicity, hepatic steatosis, hepatic necrosis, hepatic fibrosis, hepatic cirrhosis, liver injury (hepatic, cholestatic, and mixed), and liver failure.

Immune System Disorders

Angioedema, leukocytoclastic vasculitis.

Urogenital System

Acute interstitial nephritis, nocturnal enuresis, priapism, and renal failure.

Skin and Subcutaneous Tissue Disorders

Hypersensitivity reactions: photosensitivity, vasculitis, erythema multiforme, skin pigmentation disorder, and Stevens-Johnson Syndrome.

Musculoskeletal System and Connective Tissue Disorders

Myasthenic syndrome, rhabdomyolysis, and systemic lupus erythematosus.

Respiratory System

Aspiration, pleural effusion, pneumonia, lower respiratory tract infection.

Hemic and Lymphatic System

Mild, moderate, or severe leukopenia, agranulocytosis, granulocytopenia, WBC decreased, deep vein thrombosis, elevated hemoglobin/hematocrit, erythrocyte sedimentation rate (ESR) increased, sepsis, thrombocytosis, and thrombocytopenia.

Vision Disorders

Narrow-angle glaucoma.

Miscellaneous

Creatine phosphokinase elevation, hyperuricemia, hyponatremia, and weight loss.

Overdose

The information provided in Overdose of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Overdose in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
Orally disintegrating

Overdosage Experience

The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g.

Management Of Overdosage

For the most up-to-date information on the management of FAZACLO overdosage, contact a certified Regional Poison Control Center (1-800-222-1222). Telephone numbers of certified Regional Poison Control Centers are listed in the Physicians' Desk Reference®, a registered trademark of PDR Network. Establish and maintain an airway; ensure adequate oxygenation and ventilation. Monitor cardiac status and vital signs. Use general symptomatic and supportive measures. There are no specific antidotes for FAZACLO.

In managing overdosage, consider the possibility of multiple-drug involvement.

Overdosage Experience

The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g.

Management Of Overdosage

For the most up-to-date information on the management of Klozapol overdosage, contact a certified Regional Poison Control Center (1-800-222-1222). Telephone numbers of certified Regional Poison Control Centers are listed in the Physicians' Desk Reference®, a registered trademark of PDR Network. Establish and maintain an airway; ensure adequate oxygenation and ventilation. Monitor cardiac status and vital signs. Use general symptomatic and supportive measures. There are no specific antidotes for Klozapol.

In managing overdosage, consider the possibility of multiple-drug involvement.

Pharmacodynamic properties

The information provided in Pharmacodynamic properties of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Pharmacodynamic properties in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Clozapine demonstrated binding affinity to the following receptors: histamine H1 (Ki 1.1 nM), adrenergic α1A (Ki 1.6 nM), serotonin 5-HT6 (Ki 4 nM), serotonin 5-HT2A (Ki 5.4 nM), muscarinic M1 (Ki 6.2 nM), serotonin 5-HT7 (Ki 6.3 nM), serotonin 5-HT2C (Ki 9.4 nM), dopamine D4 (Ki 24 nM), adrenergic α2A (Ki 90 nM), serotonin 5-HT3 (Ki 95 nM), serotonin 5HT1A (Ki 120 nM), dopamine D2 (Ki 160 nM), dopamine D1 (Ki 270 nM), dopamine D5 (Ki 454 nM), and dopamine D3 (Ki 555 nM).

Clozapine causes little or no prolactin elevation.

Clinical electroencephalogram (EEG) studies demonstrated that clozapine increases delta and theta activity and slows dominant alpha frequencies. Enhanced synchronization occurs. Sharp wave activity and spike and wave complexes may also develop. Patients have reported an intensification of dream activity during clozapine therapy. REM sleep was found to be increased to 85% of the total sleep time. In these patients, the onset of REM sleep occurred almost immediately after falling asleep.

Pharmacokinetic properties

The information provided in Pharmacokinetic properties of Klozapol is based on data of another medicine with exactly the same composition as the Klozapol of the medicine (Clozapine). Be careful and be sure to specify the information on the section Pharmacokinetic properties in the instructions to the drug Klozapol directly from the package or from the pharmacist at the pharmacy.
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Suspension; Tablet, Disintegrating
Orally disintegrating
Absorption

In man, clozapine tablets (25 mg and 100 mg) are equally bioavailable relative to a clozapine solution. FAZACLO® (clozapine) orally disintegrating tablets are bioequivalent to Clozaril® (clozapine) tablets, a registered trademark of Novartis Pharmaceuticals Corporation. Following a dosage of 100 mg b.i.d., the average steady-state peak plasma concentration was 413 ng/mL (range: 132-854 ng/mL), occurring at the average of 2.3 hours (range: 1-6 hours) after dosing. The average minimum concentration at steady-state was 168 ng/mL (range: 45-574 ng/mL), after 100 mg b.i.d. dosing.

A comparative bioequivalence/bioavailability study was conducted in 32 patients (with schizophrenia or schizoaffective disorder) comparing FAZACLO 200 mg tablets to 2 × FAZACLO 100 mg tablets (the approved reference product) under fasted conditions. The study also evaluated the effect of food and chewing on the pharmacokinetics of the 200 mg tablet. Under fasted conditions, the mean AUCss and Cmin,ss of clozapine for the 200 mg tablets were equivalent to those of the 2 x 100 mg tablets. The mean Cmax,ss of clozapine for FAZACLO 200 mg tablets was 85% that for 2 x 100 mg FAZACLO tablets. This decrease in Cmax,ss for FAZACLO 200 mg tablets is not clinically significant.

For FAZACLO 200 mg tablets, food significantly increased the Cmin,ss of clozapine by 21%. However, this increase is not clinically significant. The mean AUCss and Cmax,ss of clozapine under fed conditions were equivalent to those under fasted conditions. Food delayed clozapine absorption by 1.5 hours, from a median Tmax of 2.5 hours under fasted conditions to 4 hours under fed conditions.

The mean Cmax,ss of clozapine under chewed conditions for FAZACLO 200 mg tablets was about 86% that for 2 x 100 mg FAZACLO tablets under non-chewed conditions, while the AUCss and Cmin,ss values were similar between the chewed and non-chewed conditions.

In a food-effect study, a single dose of FAZACLO (clozapine) orally disintegrating tablets 12.5 mg was administered to healthy volunteers under fasting conditions and after a high-fat meal. When FAZACLO was administered after a high-fat meal, the Cmax of both clozapine and its active metabolite, desmethylclozapine, were decreased by approximately 20%, compared to administration under fasting conditions, while the AUC values were unchanged. This decrease in Cmax is not clinically significant. Therefore, FAZACLO (clozapine) orally disintegrating tablets can be taken without regard to meals.

Distribution

Clozapine is approximately 97% bound to serum proteins. The interaction between clozapine and other highly protein-bound drugs has not been fully evaluated but may be important.

Metabolism and Excretion

Clozapine is almost completely metabolized prior to excretion, and only trace amounts of unchanged drug are detected in the urine and feces. Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP2D6, and CYP3A4. Approximately 50% of the administered dose is excreted in the urine and 30% in the feces. The demethylated, hydroxylated, and N-oxide derivatives are components in both urine and feces. Pharmacological testing has shown the desmethyl metabolite (norclozapine) to have only limited activity, while the hydroxylated and N-oxide derivatives were inactive. The mean elimination half-life of clozapine after a single 75 mg dose was 8 hours (range: 4-12 hours), compared to a mean elimination half-life of 12 hours (range: 4-66 hours), after achieving steady-state with 100 mg twice daily dosing.

A comparison of single-dose and multiple-dose administration of clozapine demonstrated that the elimination half-life increased significantly after multiple dosing relative to that after single-dose administration, suggesting the possibility of concentration-dependent pharmacokinetics. However, at steady-state, approximately dose-proportional changes with respect to AUC (area under the curve), peak, and minimum clozapine plasma concentrations were observed after administration of 37.5, 75, and 150 mg twice daily.

Absorption

In man, clozapine tablets (25 mg and 100 mg) are equally bioavailable relative to a clozapine solution. Klozapol® (clozapine) orally disintegrating tablets are bioequivalent to Clozaril® (clozapine) tablets, a registered trademark of Novartis Pharmaceuticals Corporation. Following a dosage of 100 mg b.i.d., the average steady-state peak plasma concentration was 413 ng/mL (range: 132-854 ng/mL), occurring at the average of 2.3 hours (range: 1-6 hours) after dosing. The average minimum concentration at steady-state was 168 ng/mL (range: 45-574 ng/mL), after 100 mg b.i.d. dosing.

A comparative bioequivalence/bioavailability study was conducted in 32 patients (with schizophrenia or schizoaffective disorder) comparing Klozapol 200 mg tablets to 2 × Klozapol 100 mg tablets (the approved reference product) under fasted conditions. The study also evaluated the effect of food and chewing on the pharmacokinetics of the 200 mg tablet. Under fasted conditions, the mean AUCss and Cmin,ss of clozapine for the 200 mg tablets were equivalent to those of the 2 x 100 mg tablets. The mean Cmax,ss of clozapine for Klozapol 200 mg tablets was 85% that for 2 x 100 mg Klozapol tablets. This decrease in Cmax,ss for Klozapol 200 mg tablets is not clinically significant.

For Klozapol 200 mg tablets, food significantly increased the Cmin,ss of clozapine by 21%. However, this increase is not clinically significant. The mean AUCss and Cmax,ss of clozapine under fed conditions were equivalent to those under fasted conditions. Food delayed clozapine absorption by 1.5 hours, from a median Tmax of 2.5 hours under fasted conditions to 4 hours under fed conditions.

The mean Cmax,ss of clozapine under chewed conditions for Klozapol 200 mg tablets was about 86% that for 2 x 100 mg Klozapol tablets under non-chewed conditions, while the AUCss and Cmin,ss values were similar between the chewed and non-chewed conditions.

In a food-effect study, a single dose of Klozapol (clozapine) orally disintegrating tablets 12.5 mg was administered to healthy volunteers under fasting conditions and after a high-fat meal. When Klozapol was administered after a high-fat meal, the Cmax of both clozapine and its active metabolite, desmethylclozapine, were decreased by approximately 20%, compared to administration under fasting conditions, while the AUC values were unchanged. This decrease in Cmax is not clinically significant. Therefore, Klozapol (clozapine) orally disintegrating tablets can be taken without regard to meals.

Distribution

Clozapine is approximately 97% bound to serum proteins. The interaction between clozapine and other highly protein-bound drugs has not been fully evaluated but may be important.

Metabolism and Excretion

Clozapine is almost completely metabolized prior to excretion, and only trace amounts of unchanged drug are detected in the urine and feces. Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP2D6, and CYP3A4. Approximately 50% of the administered dose is excreted in the urine and 30% in the feces. The demethylated, hydroxylated, and N-oxide derivatives are components in both urine and feces. Pharmacological testing has shown the desmethyl metabolite (norclozapine) to have only limited activity, while the hydroxylated and N-oxide derivatives were inactive. The mean elimination half-life of clozapine after a single 75 mg dose was 8 hours (range: 4-12 hours), compared to a mean elimination half-life of 12 hours (range: 4-66 hours), after achieving steady-state with 100 mg twice daily dosing.

A comparison of single-dose and multiple-dose administration of clozapine demonstrated that the elimination half-life increased significantly after multiple dosing relative to that after single-dose administration, suggesting the possibility of concentration-dependent pharmacokinetics. However, at steady-state, approximately dose-proportional changes with respect to AUC (area under the curve), peak, and minimum clozapine plasma concentrations were observed after administration of 37.5, 75, and 150 mg twice daily.

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